1. Technical Field
The present disclosure relates to a safety trocar assembly incorporating a structure to prevent overpenetration of the safety trocar assembly into an abdominal cavity. More particularly, the present disclosure relates to a safety trocar assembly incorporating an airbag and sensors associated with a distal end of the safety trocar assembly for detecting changes in conditions at the distal end of the safety trocar assembly.
2. Background of Related Art
During minimally invasive surgical procedures access ports or trocar assemblies are provided to penetrate an abdominal wall and provide a sealed pathway for insertion of surgical instruments into an abdominal cavity. These trocar assemblies typically include an access port or cannula having a housing and an elongate tubular member extending distally from the housing. A channel or lumen extends through the housing and elongate tubular member for receipt of surgical instruments. One or more valves or seals may be provided within the housing to seal against the surgical instruments. The trocar assemblies additionally include a tissue penetrating or incising device or obturator which is positioned through the cannula. The obturator typically includes a tissue penetrating tip at a distal end which, when assembled with the cannula, extends beyond the distal end of the cannula. Advancement of a trocar assembly against an abdominal wall causes the tissue penetrating tip of the obturator to penetrate the abdominal wall and allow passage of the distal end of the cannula into the abdominal cavity.
During insertion of the trocar assembly through the abdominal wall, care must be taken not to damage underlying organs by engagement with the tissue penetrating tip of the obturator or the distal end of the cannula. Various types of safety devices have been developed to shield underlying organs from the tissue penetrating tip of the obturator. In one type of safety trocar assembly, the obturator is maintained in a distal position relative to the cannula during insertion and is spring biased proximally such that upon penetration into the abdominal cavity the tissue penetrating tip of the obturator retracts within the distal end of the cannula. This shields underlying organs from the tissue penetrating tip of the obturator. In another type of safety trocar assembly, a spring biased outer sheath or shield is associated with the cannula such that, upon penetration of the abdominal wall by the tissue penetrating tip of the obturator, the outer sheath or shield advances distally to cover the tissue penetrating tip of the obturator again preventing damage to underlying organs.
While the known type of safety trocar assemblies incorporate methods of shielding underlying organs from the tissue penetrating tip of the obturator, these safety devices do not prevent continued advancement of the trocar assembly through the abdominal wall towards the underlying organs.
Therefore, a need exists for a safety trocar assembly which incorporates an expandable member located proximally of the distal end of the safety trocar assembly to prevent overpenetration of the safety trocar assembly through the abdominal wall. Further, a need exists for a safety trocar assembly having a sensor adjacent the distal end of the safety trocar assembly to detect changes in conditions at the distal end of the safety trocar assembly as it passes through the abdominal wall and into the body cavity.